• Convergence Security Journal
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• v.18 no.1
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• pp.85-91
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• 2018

In this study, we design a marine environmental information service system with satellite images based on satellite images to reduce the damage caused by changes in the marine environment. The system provides satellite oceanographic information such as water temperature, chlorophyll, float, etc. as hierarchical texts, which is implemented as a unit module Web service so that it can be expanded in OpenAPI environment. And stability of system plug-in portability, service hours, data extraction precision and speed are used as a basis for diagnosing service stability. By securing the function and performance of the service system implemented in this study, it can be expanded to a complex technology that can customize the users by group by adding not only general services of existing systems operated by location but also information about a specific interested areas. Especially, various other items of interest including marine environment information are developed in modules, so we expect to be able to expand and service the system by plugging into the system and to spread it in technical linkage with the related institution information system.

• Journal of Energy Engineering
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• v.25 no.2
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• pp.45-51
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• 2016

The pool water management system, which is installed for purification of the coolant in the pools and the primary cooling system of a research reactor, removes the decay heat from the reactor core when the primary cooling system stops. It also removes the heat generated from the irradiated objects in the service pool and the spent fuels in the spent fuel storage pool to keep the temperature of the pools within a limited value. In this study, the heat exchanger of the pool water management system is designed by CFD method using a commercial code Flowmaster, and the temperature of the pools is estimated along the time to conclude the design and operation method of the pool water management system.

• Journal of Korea Water Resources Association
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• v.40 no.9
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• pp.735-742
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• 2007

In this study, a methodology which is based on segments and minimum outsets to estimate the reliability of a real water distribution system efficiently and accurately is suggested. The current reliability assessment models based on minimum cutset consider a pipe as only area impacted by a pipe failure which incurs underestimation of pipe failure impact. In contrary, the suggested methodology adopts "segment" and "unintended isolation" with the hydraulic pressure failure area to define the actual service interruption area in a water distribution system due to a pipe failure, which is different from the Previous reliability estimating methodologies. In addition, a minimum cutset is defined as a single segment incurring abnormal operating conditions and the success mode approach is used to account for the probability of multiple failure combinations of minimum outsets. The model considers numbers and locations of on-off valves when the service interruption area is defined. Once the methodology is applied to a real water distribution system, it is possible to define actual service interruption areas and using the defined areas, the reliability of the water distribution system is estimated reliably, compared with the previous reliability assessment methodologies.

• Journal of Korean Society of Water and Wastewater
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• v.35 no.3
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• pp.237-246
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• 2021

The ILI, developed by the IWA (International Water Association), has been used in many countries as an indicator of water leakage. In Korea, the revenue water has been used as a performance indicator for waterworks although there is an opinion to replace it with the ILI. Hence, it has been necessary to investigate whether the ILI can replace the revenue water in Korea. The four main operating indicators (i.e., water service population, profit-loss ratio, fiscal self-reliance, and aged pipe rate) of 162 Korean waterworks were compared with the ILI with the linear regression method. Local water authorities with more than 1 million water service population, with more than 60% profit-loss ratio, more than 40% and less than 60% fiscal self-reliance, and more than 20% aged pipe rate showed meaningful correlation between the four parameters and the ILI. In the remaining cases, their correlations were little or weak. This means that using the ILI may not be an efficient method to represent the performance of the water supply system in Korea because of the lack of UARL (Unavoidable Annual Real Losses) data accuracy. To use the ILI in Korea, it will be required to carry out an additional research to accumulate reliable CARL (Current Annual Real Losses) and UARL data in the future.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.4D
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• pp.535-544
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• 2009

Even though Korea's national project - NGIS(National Geographic Information System) has been built since 1995 and the GIS database for underground facilities has also been built, not so many systems are utilizing those databases currently. Also, the waterworks GIS developed and operated by K-Water is not used effectively in supporting field works. In order to manage and operate the waterworks pipelines effectively, systematic supporting strategy must be established by adopting the state-of-the-art technology. In this research, a ubiquitous-based strategy for managing waterworks facilities is proposed to increase the usability of the existing related databases and to ensure the systematic way of distributing information. The current status of the existing waterworks GIS and GIS database were analyzed to achieve the goal. By studying the state-of-the-art technology, we found that importing the LBS technology to the databases is necessary. The results of these efforts are exclusive waterworks-mobile-terminals and LBS system supporting them. Furthermore, the applicability of the ubiquitous technology to waterworks has been examined to realize the real-time waterworks management.

• Journal of Agricultural Extension & Community Development
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• v.17 no.4
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• pp.685-716
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• 2010

The purposes of this study were to exploring the rural residents' satisfaction of living environment and social service. For these purpose we collected the data from the residents in rural area(1,000). The major findings of this study were as follows : First, the total satisfaction score is 58.9. The highest score group is housing and environment(69.9). And the lowest score group is cultural life and leisure environment. Various welfare services have been carried out for low income people, disabled people, old people, children and rural women within the social service system. But many respondents did not have chances to use social service because it was not efficiently provided many social services. So most of the residents in village wanted more welfare services. Second, the qualitative enhancement is more important than physical infrastructure expansion in order to improve rural settlement condition(housing quality, water supply and drainage, road and traffic system, medical care etc.)

• Journal of the Korean Ceramic Society
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• v.54 no.2
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• pp.114-120
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• 2017

In underdeveloped countries, many people suffer from water shortage due to the absence of water supply service. Although water purifiers have provided support in such situations, it is not easy to maintain water filters without a continuous supply of consumable filters. To obtain a sustainable drinking water source, appropriate technology of water treatment is necessary. Herein, a low cost water purification system was developed using natural raw materials. A non-electric water treatment system was developed using filtration through an Onggi filter, which is a type of Korean traditional earthenware with a microporous surface. The porosity and flux of the prepared Onggi filter were 29.06% and 31.63 LMH, respectively. After purification of water with total dissolved solids of 10.4 mg/L and turbidity of 100 NTU, the total dissolved solids and turbidity of the water treated using the Onggi filter decreased by 12% and 99.8%, respectively.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.1
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• pp.15-25
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• 2013

The RIMGIS(River Information Management GIS) has been developed since 2000 for public service and practical applications of related works after the standardization of national river data such as the river facility register report, river survey map, attached map, and etc. The RIMGIS has been improved in order to respond proactively to change in the information environment. Recently, Smart River-based river information services and related data have become so large as to be overwhelming, making necessary improvements in managing big data. In this study a plan was suggested both to respond to these changes in the information environment and to provide a future Smart River-based river information service by understanding the current state of RIMGIS, improving RIMGIS itself, redesigning the database, developing distribution, and integrating river information systems. Therefore, primary and foreign key, which can distinguish attribute information and entity linkages, were redefined to increase the usability of RIMGIS. Database construction of attribute information and entity relationship diagram have been newly redefined to redesign linkages among tables from the perspective of a river standard database. In addition, this study was undertaken to expand the current supplier-oriented operating system to a demand-oriented operating system by establishing an efficient management of river-related information and a utilization system capable of adapting to the changes of a river management paradigm.

• Journal of Korean Society on Water Environment
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• v.20 no.3
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• pp.206-214
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• 2004

Residual wall thicknesses, corrosion rates, and residual life of thirty four samples of cast iron pipes(CIPs) and ductile cast iron pipes(DCIPs) collected from water mains of B city were studied to estimate their remaining service life or optimum time of rehabilitation. The internal maximum corrosion depths of samples measured using a dial gauge after shot blasting were twice higher than the external in most cases. Therefore corrosion of water pipes was much more affected by internal water quality than soil. Residual wall thicknesses of DCIPs were higher than those of CIPs. That reason was thought to be that DCIPs have been protected from internal corrosion by lining cement mortar. Residual life calculated by maximum corrosion rate was ranged up to 44 years with 12.40 years average. Since most CIPs were much deteriorated, rehabilitation plan should be established soon in B city. Residual life of DCIP was 33.52 years average. When cement mortar lining is used up by neutralization of DCIPs. DCIP also should be rehabilitated.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.6
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• pp.587-597
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• 2017

This study aimed to develop a method to optimize residual chlorine concentrations in the process of providing water supply. To this end, this study developed a model capable of optimizing the chlorine input into the clearwell in the purification plant and the optimal installation location of rechlorination facilities, and chlorine input. This study applied genetic algorithms finding the optimal point with appropriate residual chlorine concentrations and deriving a cost-optimal solution. The developed model was applied to SN purification plant supply area. As a result, it was possible to meet the target residual chlorine concentration with the minimum cost. Also, the optimal operation method in target area according to the water temperature and volume of supply was suggested. On the basis of the results, this study derived the most economical operational method of coping with water pollution in the process of providing water supply and satisfying the service level required by consumers in the aspects of cost effectiveness. It is considered possible to appropriately respond to increasing service level required by consumers in the future and to use the study results to establish an operational management plan in a short-term perspective.